Coating composition



Patented Aug. 23, 1938 COATING COMPOSITION Walter E. Gloor, Parlin, N. J., assignor to Hercules Powder Company, Wilmington, Del., a corporation of Delaware 1 No Drawing. Original application September 23, 1936, Serial application May 12 Claims.

This invention relates to esters of aliphatic polyhydric nitro-alcohols with monobasic organic acids and to compositions in which such organic esters are present as an ingredient.

I An object of this invention is the provision of a new group of chemical compounds which are of particular advantage as plasticizers for cellulose esters, as nitrocellulose, cellulose acetate,

etc., cellulose ethers, chlorinated rubber, natural l .resins, etc.

A further object of this invention is to provide compositions of cellulose acetate plasticized with monobasic organic esters of aliphatic polyhydric nitro-alcohols which are particularly adapted for use as molding compositions.

The new esters inaccordance with this invention are esters of an aliphatic polyhydric nitroalcohol, and are characterized by containing somewhere in their structure an aliphatic -C.--NO2 group. This group of compounds is entirely distinct from the aliphatic nitrates which contain the group -'C--ONO2, and from the aromatic nitro compounds which contain the N6: group linked to a carbon atom in an aromatic ring.

The method in accordance with this invention consists of esterifying an aliphatic polyhydric nitro-alcohol with a monobasic organic acid or an anhydride of a monobasic organic anhydride. The aliphatic polyhydric nitro-alcohol which I may esterify is characterized by. containing somewhere in its structure the -C-NO2 group and two or more hydroxyl groups, and may be, for example, trimethylol nitromethane, dimethylol nitroethane, tri-=alpha-ethylol nitromethane, dimethylol nitropropane, dimethylol nitrobutane, 1-1 dimethylol-1-nitro-4-hydroxy butane, etc.

The aliphatic polyhydric nitro-alcohols which I may esterify may be conveniently prepared by the condensation of an aldehyde with an aliphatic compound containing a nitro group, such as, for

, example, a intro-hydrocarbon, a nitro-alcohol, etc. Thus, for example, dimethylol nitro ethane maybe prepared by the alkaline condensation of formaldehyde with nitroethane. Triethylol nitromethane may, be similarly prepared by the condensation of acetaldehyde with nitromethane.

Similar aliphatic polyhydric nitro-alcohols may,

9 ior example, be prepared by the condensation of formaldehyde with l-nitropropane, 2-nitropropane, l nitro-2-methyl propane, etc.

The monobasic. organic acid which I may use to esterifyi'the aliphatic polyhydric nitro-alcohol n ay be any, monobasic organic acid which is 24, 1937, Serial No. 144,538

reaction at a temperature Divided and this sufflciently reactive to undergo an esterification the aliphatic polyhydric nitro-alcohol is rapidly decomposed, such as, for, example, the lower fatty acids, as, acetic acid, propionic acid, butyrlc acid, benzoic acid, toluic acid, etc. The tempera ture at which the rate of decomposition of an aliphatic polyhydric nitro-alcohol decomposes depends upon the particular alcohol and upon the condltions of reaction. It will, however, be found that the rate of decomposition oi! an aliphatic polyhydric nitro-alcohol in an esteriflcation me-' dium does not become rapid at a temperature below 210 C.

The anhydride of a monobasic organic acid which I may use to esterify the aliphatic polyhydric nitro-aicohol may be an anhydride of any "monobasic organic' acid, which is suiiiciently reactive to undergo an esteriflcation reaction at a temperature below that at which the aliphatic polyhydric nitro-alcohol is rapidly decomposed, such as, for example, the anhydrides of acetic below that at which acid, propionic acid, butyric acid, benzoic acid,

toluic acid, etc.

The'esterification reaction, in accordance with this invention, will desirably be carried out at a temperature below 210 C., and preferably within the range of about 100 C. to about 150 C. The reaction will preferably be carried out in the presence of an esterification catalyst, such as, for example, zinc chloride, p-toluene sulfonic acid, benzene sulfonic acid, xylol sulfonic acid, sulfuric acid, pyridine, etc.

In the esterification reaction, in accordance with this invention, the removal of the water produced in the reaction is facilitated by carrying out the reaction under reflux in the presence of an azeotrope such as toluene, separating water from the condensate, and returning the azeotrope to the reaction. Alternately, the anhydride of the acid of which the ester is desired, is reacted with the aliphatic polyhydric nitro-alcohol in the presence of pyridine with 'or without one of the otheresterification catalysts mentioned.

The following examples further illustrate the method in accordance with this invention.

EXAMPLE I Preparation of dimethylol nitroethane diacetate One mol. (101 grams) of dimethyl nitroethane'and 2.4 mols (144 grams) of glacial acetic acid were mixed with 75 grams of toluol and 2 grams of p-toluene sulfonic acid. This mixture EXAMPLE II I Preparation of trimethylol nitromethane tripropionate One mol. (151 parts by weight) of trimethylol nitromethane was refluxed for three hours with 7.2 mols (938 parts by weight) of propionic anhydride in the presence of one mol. (79 parts by weight) of pyridine and 2.0 parts by Weight of zinc chloride. This reaction mixture was then cooled, poured into ice water and allowed to stand until the unreacted propionlc anhydride is decomposed. This mixture was then extracted with ether, the ether extract neutralized, dried,

and the ether evaporated. The product is then obtained in purified form by vacuum distillation, and is trimethylol nitromethane tripropionate.

The chemical formulas and properties of representative products in accordance with this in- 56%, etc., cellulose acetopropionate, cellulose acetobutyrate, ethyl cellulose, chlorinated rubber, etc., and will be found to be valuable plasticizers in coating compositions and molding'plastics of various types. 5

The products in accordance with this invention are particularly suitable for use either alone or in admixture with other plasticizers, as plasticizers in cellulose acetate plastics. These products give good colloiding and non-evaporating properties in plastics and will be found to be highly resistant to heat, light, and water, and to be good solvents for poorly miscible material, such as triphenyl phosphate.

' The following table illustrates compositions, made in accordance with this invention, which are suitable for use as molding plastics.

Table II 20 ExampleNo. 1 2 3 4- 6 G 7 8 Cellulose acetate (52% acetic acid) Dlmethyloi nltroethane dlpropiomite Dimethylol nitropropane dlpropionatc Trimcthylui nitromethane tnacotrite 'irhncthylol nitromethanc tripropionatc Tritmethylol nitromethnne tributyra e Dimethylolnitroethanediacetnte.-. 'Iriethyloi nitromethane diacetate-- Methyl phthalyl methylglycollate vention are given in the following table: i

Table I Name Formula 83; :5 32 21 3322 11 1: 26 O. 0. 5-10mm.

mcoodcm .0. o Trimethyiol nitromcthane triacetate CHLCOOCH N0 4 1. 289 1.4585 -170 mcoo 0.0111011. Trimethylol nitromethane tripropioriate.. CH;.CH1.C00.CHr-CN01 A 1.171 1. 4480 170-185 6 mcoocomeincm Trimethylol nltromethane tri-butyrate cmomomcooom-c-rro. 1.115 1.4480 186-116 H1 DOC-CHl-CHa-CH1 5o H1C.OO( 'J.CH1 Dlmethylol nitroethana diaeetate CH1. No, I 1.20 1. 4425 152-100 H. .oo'ccm H|C.OOC.CH1.CH1 55 Dimethyiol nitroethane dipropionata CH1. .NO, 1.142 1.460 160-166 H: .0OO.OH|.OH|

, K100000150 Dimethylol nitropropane diacetute CH1.CH1. .NO| 1.152 1.4363 -168 00 H1 ooccm cmcnoodcm Tri-oipha-cthylol nitromethenelrlacetate CH1.COOC- -NO1. 1.4467

c1:1ooo.cm (1H1 The products in accordance with this invention I Plastics may be prepared from the above com- 7 are soluble in aromatic hydrocarbons, alcohols, positions by colloiding the composition, as, for esters, and ketones; They are compatible with example, with the aid of a mixture of equal parts nitrocellulose of various types, as the esteralcohol and acetone on a differential two-roll mill. soluble, and the alcohol-soluble type, cellulose The plastic so produced may be sheeted and then acetates of various acetic acid contents, as, 52%, molded into the desired form, and will be found 75 to be tough, water-resistant, well bonded and of good clarity.

It will be understood that the details and examples hereinbeiore set forth are illustrative only,

and that the invention as herein broadly de- 2. A composition of matter comprising an ester of an aliphatic polyhydric nitro-alcohol with a -monobasic organic acid and a cellulose ester;

3. A composition of matter comprising an ester of an aliphatic polyhydric nitro-alcohol with a monobasic organic acid and cellulose acetate.

4. A composition of matter comprising an ester of an-aiiphatic polyhydric nitro-alcohol with an aliphatic monobasic organic acid and cellulose acetate.

5. A composition of matter comprising an ester.

of an aliphatic polyhydric nitro-alcohol' with a lower fatty acid and cellulose acetate.

6. A composition of matter comprising an ester or an aliphatic polyhydric nitro-alcohol with acetic acid and cellulose acetate.

7. A composition 0! matter comprising an ester 0! an aliphatic polyhydric nitro-aicohol with propicnic acid and cellulose acetate.

8. A composition of matter comprising an ester oi! an aliphatic polyhydric nitro-alcohol with butyric acid and cellulose acetate.

9. A composition of matter comprising trimethylol nitromethane triacetate and cellulose acetate.

10. A composition of matter comprising trimethylol nitromethane tripropionate and cellulose acetate.

11. A composition of matter comprising trimethylol nitromethane tributyrate and cellulose acetate. v

12. A composition oimatter comprising an ester of an aliphatic polyhydric nitro-alcohol with a monobasic organic acid and a solid film-forming material selected from the group consisting of cellulose esters, cellulose ethers, chlorinated rubber and natural resins.

WALTER a. moon. 

